This fruitfulness was evidenced, not only by Pasteur’s personal labours, but by those he inspired and encouraged. Thus, in that same period, M. Gayon, a former student of the Ecole Normale, whom he had chosen as curator, started on some researches on the alteration of eggs. He stated that when an egg is stale, rotten, this is due to the presence and multiplication of infinitesimally small beings; the germs of those organisms and the organisms themselves come from the oviduct of the hen and penetrate even into the points where the shell membrane and the albumen are formed. “The result is,” concluded M. Gayon, “that, during the formation of those various elements, the egg may or may not, according to circumstances, gather up organisms or germs of organisms, and consequently bear within itself, as soon as it is laid, the cause of ulterior alterations. It will be seen at the same time that the number of eggs susceptible of alteration may vary from one hen to another, as well as between the eggs of one hen, for the organisms to be observed on the oviduct rise to variable heights.” If the organisms which alter the eggs and cause them to rot “were formed,” said Pasteur, “by the spontaneous self-organization of the matter within the egg into those small beings, all eggs should putrefy equally, whereas they do not.” At the end of M. Gayon’s thesis--which had not taken so long as Raulin’s to prepare, only three years--we find the following conclusion: “Putrefaction in eggs is correlative with the development and multiplication of beings which are bacteria when in contact with air and vibriones when away from the contact of air. Eggs, from that point of view, do not depart from the general law discovered by M. Pasteur.” Pasteur’s influence was now spreading beyond the Laboratory of Physiological Chemistry, as the small laboratory at the Ecole Normale was called. In the treatise he had published in 1862, criticizing the doctrine of spontaneous generation, he had mentioned, among the organisms produced by urine in putrefaction, the existence of a torulacea in very small-grained chaplets. A physician, Dr. Traube, in 1864, had demonstrated that Pasteur was right in thinking that ammoniacal fermentation was due to this torulacea, whose properties were afterwards studied with infinite care by M. Van Tieghem, a former student of the Ecole Normale, who had inspired Pasteur with a deep affection. Pasteur, in his turn, completed his own observations and assured himself that this little organized ferment was to be found in every case of ammoniacal urine. Finally, after proving that boracic acid impeded the development of that ammoniacal ferment, he suggested to M. Guyon, the celebrated surgeon, the use of boracic acid for washing out the bladder; M. Guyon put the advice into practice with success, and attributed the credit of it to Pasteur.